Former Navy petty officer Anthony Parsons, also known as Tony, was reported missing in 2017, aged 63, while on a charity cycle from his home in Tillicoultry, Clackmannanshire, to Fort William.
He was last seen at around 11.30pm on October 2 that year outside the Bridge of Orchy Hotel in Argyll.
His remains were discovered in January this year in a remote area of ground close to a farm near the A82 at Bridge of Orchy.
Police Scotland said on Monday two men were arrested and charged in connection with his death.
Twins Alexander McKellar and Robert McKellar, both 29, appeared at Dumbarton Sheriff Court accused of murder, conspiracy to murder and an attempt to defeat the ends of justice.
Alexander McKellar is also accused of causing serious injury by dangerous driving.
The twins, from Argyll, made no plea at the private court hearing and were remanded in custody pending a further court date.
At a funeral service for Mr Parsons at Stirling Crematorium in April, his family urged anyone with information to come forward, saying they “still need answers” about his death.
Detective Inspector John McFall of the Major Investigations Team said: “I would like to offer my thanks to the local community for all their help and assistance throughout this investigation and to those who came forward with significant information.”